smith



A. R. SMITH. POWER PLANT. APPLICATION FILED DEC. 15. 1920.

1,390,062. t sept 6,1921.

flFid I f I I I is 75' 1e 67 3 F i g.2. 9 65 Inventor:

Arthur R.Smith, b8

l-l is Attorneg ARTHUR B. SMITH,

UNITED STATES PATENT, OFFICE;

or SCH ENECTA DY, imw YORK, ASSIGNORTO GENERAL commune CORPORATION or NEW YORK.

ELECTRIC POWER PLANT. I

' To all whom it may concern power. The prime movers now in general use are steam turbines and in the following description I describe my invention as carried out lnconnection' with steam turbogenerator sets. It will be understood, however, that this is only by way of example to heat the feed water.

and that other types ofprime movers may be utilized if found desirable.

In power plants there are a number of small auxiliaryfdevices, such as circulating pumps, fans, blowers, etc. to be driven and my invention relates particularly to plants .wherein such. auxiliaries are driven by electric motors, a small turbo-generator. set, termed a house turbine. belng provided" for furnishing'power'to such motors, the exhaust from the house turbine being utilized As is well understood, the feed water comprises the'condensate from the main turbo-generator set plus the required amount of make-up water.

The use of a so-termed Fhouse turbine for furnishing power for driving v y the auxiliaries, rather than taking such power from the main unit. is desirable because when excessive reductions in voltage orfrequency such a'portion ofthe auxiliary load is 'car ried by the house turbin'e'as to cause the turbine to furnish suflicient exhaust steam to heat the feed 'water to a certain or pre- & which can be determined by calculation.

Specification of Letters Patent.

Patented Sept. 6, 1921.

Application filed December 15, 1920. Serial No. 430,861.

According to; my invention, 1. provide an automatic controlling means for the house turbine whereby the load .on it will be so regulated that the exhaustffrom it will be just sufficient to heat the feed water to the 'desiredtemperature, the remainder of the auxiliary load "being carried by the main IlIllt, the arrangement being such that't'he auxiliary load will be automatically shifted from the house turbine to the main unit and back again as the requirements for exhaust steam'vary.- F orautomatically controlling the house turbine I preferably provide an arrangement responsive to the exhaust pressure of the house turbine and whlch operates to maintain such exhaust pressure constant or'substantiallv constant. The generator of the house turbine set is connected to bus-bars 'from which leads extend to the motorsfof the auxiliariesfand the generator of the main set is likewise connected to such bus-bars either directly or through. the medium of a motor generator set, transformer or the like. according to the requirements of the particular system. Thetwo generatorsare thus connected to the auxiliary load'in parallel.

In the drawing, Figure 1 shows diagrammatically a power plant embodying my invention, and Fig. 2 illustrates a modification. I

Referring to the drawing, 5' indicates a main turbine driving a generator 6 which is electrically connected by leads 7 to busbars 8.. In leads ,7 is a suitable circuit breaker 7*. The exhaust end of the turbine is connected to a condenser 9 and condensate 'from the condenser is pumped by a pump 10 to a 'hotwell 11, The suction side of pump 10 is connected to condenser 9 by a pipe 12 and the discharge side of the pump is connected to the hot well by a pipe 13.' A power plant may have a single main turbo-generator unit or it may have two or more connected in parallel or otherwise,"and at 14 I have indicated a pipe which may lead from the condenser of another main unit and discharge into the hot well through'pipe 13 also. At 15 and 16 are feed water pumps which pump water from hot well 11 to the boilers of the power plant (not shown) and as is well understood this feed water may be passed through eoonomizers prior to being fed into'the boilers so as tohave its temperatureraised still higher. 'M v The bus-bars from which power is taken to drive the auxiliaries are indicated at 17 and the leads indicated at 18 extend to the motors which drive the various auxiliary devices. For example, some of them may he leads connecting to the motors which drive pumps 10, 15, and 16.

Power for driving the auxilaries is supplied to bus-bars 17 from a house turbine set and from the main turbo-generator set which are connected to bus-bars 17 in parallel. In the present instance it has been assumed that the auxiliaries are driven by direct current motors and that the main generator 6 is an alternating current generator. Generator 6 is accordingly connected to bus-bars 17 through the intermediary of a motor generator set. Leads 19 connect the generator 20 of the motor generator set to bus-bars 17, the motor 21 or" the set being connected to bus-bars 8 by leads 22. The motor generator set thus takes power from bus-bars 8, i. e. the main turbo-generator unit. and delievers power to bus-bars 17. In leads 19 and 22 are suitable circuit breakers 23 and 24 respectively.

Connected to bus-bars 17 by leads 25 is a generator 26 driven by a turbine 27, such a turbo-generator set being termed a house tubine as stated above. In leads 25 is a suitable circuit breaker 25. The exhaust end of turbine 27 is connected to a ct condenser 28. Hot well 11 is divided into two compartments 29 and 30 by'a partition wall 31. Compartment 29 is smaller than compartment 30 and the two are connected to each other at the top, this being effected in the present instance by making wall 31 terminate shortof the top of the hot well. Leading from the bottom of compartment 29 is apipe 82 which connects with the suction side of a pump The discharge side of pump 33 is connected by a pipe to the condensing or cooling water inlet of jet condenser 28. Disch rge tube 35 of jet condenser 28 terminates in compartment 29 below the level of the water therein. At 35 is an atmospheric exhaust provided with a loaded outwardly opening check valve 35 I Pipe 13 which conveys condensate from the main condenser or condensers extends down into compartment 29 of the hot well and terminates directly adjacent the inlet end of pipe 32 so that in substance it dis charges directly into such pipe. At 36 is a feed water make up supply pipe and this also extends down into compartment 29 and terminates directly adjacent the inlet end of pipe 32. it will thus be seen that the condensing or cooling water supplied by pump 33 to jet condenser 28 is the condensate from the main condenser or condensers and the feed water make-up.

Pipe 36 may lead from any suitable supply of feed water and is provided with a valve 38 around which is a by-pass pipe 39 provided with a valve 40. Valve e0 has an operating arm 41 which is connected by a link 42, lever s3, and red as to a float 15. Float 4C5 rides on the water in compartment 30 and as the level raises or lowers it acts to shut or open valve &0. Vith this arrangement valve 38 is set by hand so there is sup plied through it an amount oi make up feed water less than the minimum required. The remainder is then supplied through valve it). By this arrangement float 15 acts on only a fractional part or the total make up feed water and as a result a closer regulation can be obtained.

Connected in series with the field of generator 26, which field is indicated at 26, is a regulating resistance 46 having a contact arm 47 adapted to be moved to cut resistance in and out of the generator field. Connected to contact arm M is a toothed segment 48 with which meshes a rack 49 connected to a piston 50 which moves in a cylinder 51. Associated with cylinder 51 is a pilot valve 52 which controls the supply of actuating fluid to the cylinder. This forms an ordinary type of servo-motor or hydraulic motor. the operation of which is well understood. The stem of pilot valve 52 is connected to a diaphraga n 53 located in a casing 5% and connected to casing 5st below the diaphragm is a pipe 55 which leads from jet condenser 28. Diaphragm 53 forms therefore a movable abutment which is subjected to the pressure existing in the condenser. At 56 is a suitable spring for adjusting the setting of the movable abutment or pressure responsive device 53, the spring shown being under tension and acting to move the diaphragm upward.

The operation is as follows :Assume the main turbo-generator set is in operation and carrying a certain load and all auxiliaries are in operation. Also that the pressure rcsponsive device is set to hold a certain exhaust pressure in condenser 28. Under these circumstances a part of the auxiliary load may be carried by the house turbine and the remainder by the motor-generator set, 2'. c. by the main turbo-generator set. A certain amount of the regulating resistance 16 may he in series with generator field 26. It now the load on the main turbo-generator set in creases which means that it will require more steam and hence that there will be more condensate, such additional condensate in passing through jet condenser 28 will act to increase the vacuum created e., decrease the back pressure, on house turbine 27, and at the same time the temperature to which the water is heated in passing through such condenser will decrease. As a result of the increase in vacuum, diaphragm 53 will move downward thereby lowering pilot valve 52 and admitting actuating fluid beneath pis ton 50. This raises piston 50 and turns conit and hence the temperature to which the water passing through condenser 28 is heated tact'arm 47 to decrease the resistance in se-' ries'with generator field 26 and thus increases the load on the house turbine. result the house turbine will take more steam inorder to carry such additional load which means that there will be more exhaust from will be increased and the vacuum decreased. The additional load taken by the house turbine will be taken from the motor-generator set thus decreasing the load carried by it. T On the other hand, should the load. on the main turbine decreasethereby decreasing the amount of condensate available for use in jet'condenser 28, the vacuum the jet condenser will decrease with the result that the pressure responsive device will operate to cut resistance intothe generator field thereby decreasin'gthedoad on the turbine andincreasing the load on the motor-generator set. In connectionfwith the house turbine it'will be understood of course that it is provided with the usual regulating mech- 'anism' (not shown) for supply steam in accordance'iwith the load as is common and "well known in 'the art.-- Shou1d themain turbine 5 shutdown, due, forexample, to a short circuit 'or' other cause, the circuit breaker 23 will immediately open thereby disconnecting the motor generatorset from i ,bus-bars'l'fl, The house turbine willthen carry the' entire-"load "of the auxiliaries. Upon suchan occurrence the housje turbine will operate non-condensing,exhausting to atmosphere through the exhaust conduit 35. i The closing down prevented.

of the whole plant is thus It will thus be seen" that the arrangement operates automatically to maintain a substantially-constantexhaust pressure for the house turbine and that only sufiicient load is carried by I the house turbine to supply enough exhaust steam for maintaining such pressure. I In other words the steam'used in the house turbine is only such as will supply an amount of exhaust-steam which can be efiiciently utilized for heating the feed water.

Fig. 2 shows :an arrangement similar to that shownin Fig. 1 except that the pressure regulator instead of operating on a resistance in series with the generator field for varying the load on the house turbine operates onthe speed governorof the house turbine to vary its setting, thus accomplishing the same/result. ,In'Fig. 2, 27 indicates theturbineof the house turbinese't and a speed governor which controls the admission ofelastic fluid to it, the governor beingconnected to the regulating mechanism.

foradmitting steam to the turbine through a governor lever 61 and-a rod 62., Connected to. governor lever 61 is a synchronizing springstructure indicated at 63 which isadapted to be operated. to vary the setting Asa turbine to the motorgenerator set.

of the governor by a motor 64. Motor 64 is connected to a suitable source of power as indicated at 65 through a'reversing switch 66. Switch arm 67 of the'reversing switch has connected to it a toothed segment 68with which meshes arack 69 carried by a rod 70. .Rod70 is connected to the piston 71 of a servo motor orhydraulic motor, the pilot valve of which'is shownat 72. The stem of pilot'valve 72 is connected to a movable abutment of thevsame character as that shown in Fig. 1' at 53, the same being indi-- cated bythe'numeral 53; 55 is a pipe corresponding to pipe 55 of Fig. 1 and performing the same functions, it serving to connect the movable abutment to the jet condenser of p the house turbine. The operation of the arrangement shown in F 1g; 2 is the same in general as that shown in Fig. 1 except that, :as already stated, the regulating device which responds to thevacuumof the jet condenser actson the turbine governor. With an increase in vacuum movable abutment 53 will be actuatedto close reversing switch 66 to effect operation of motor 66 in a direction to load the governor therebycausing the house turbine totake more load, while. with a, decrease inythe load, the switch will be closed to operate the motor in the opposite direction to "unload the governor thereby shifting some of" the loadjfrom the house Theiar rangement shown in Fig. .2 is well adapted for use in case alternating current motors are used to drive'theauxiliaries although it may be used with a' direct current drive.

In this connection it will be understood that in case the auxiliaries are driven by alter I desire to have it understood that the apparatus shown is only illustrative and that the invention maybe carried out by other means. v v r What I claim as new and desire to secure by Letters Patent of 'the United States, is T 1. A power, plant having a mainv prime mover driven generator set,-,motor "driven auxllariesf, and aprimemover driven generator set for supplying power to the mo-' tors of the auxilaries, characterized bythe fact that condensate from the condenser for the main primeimover. is used as cooling liquid in the condenser for the second named, prime mover, and theteinperature to which the condensate used for cooling purposes in the condenser of the second named prime mover is heated is kept substantially constant by automatically varying the load on the second named prime mover.

2. A power plant having a main prime mover driven generator set, motor driven auxiliaries, and a prime mover driven generator set for supplying power to the motors of the auxiliaries characterized by the fact that condensate from the condenser for themain prime mover is used as cooling liquid in the condenser for the second named prime mover, and the temperature to which the condensate used for cooling purposes in the condenser of the second named prime mover is heated is kept substantially constant by automatically varying the load on the second named prime mover, the remainder of the load beingv carried by the first named prime mover.

3. In a power plant, a main prime mover, a generator driven thereby, a second prime mover. a generator driven by it, a condenser for the second named prime mover which utilizes condensate from the first named prime mover as cooling liquid, and means for maintaining automatically such a load on the second named prime mover that its exhaust will heat the condensate used in its condenser to a predetermined temperature.

4. In a power plant, a main prime mover, a generator driven thereby, a second prime mover, a generator driven by it, a condenser for the second named prime mover which utilizes condensate from the first named prime mover as cooling liquid, and means automatically controlled by the pressure in the condenser of the second named prime mover for automatically maintaining a substantially constant pressure therein.

A power plant having a main prime mover driven generator set, motor driven auxiliaries, and a prime mover driven generator set and a motor generator set connected in parallel for supplying power to the motors of the auxiliaries, the motor generator set being connected to the first named generator, characterized by the fact that condensate from the condenser for the main prime mover is used as cooling liquid in the condenser for the second named prime mover. and the temperature of the condensate of the second named prime mover is automatically kept constant or substantially constant by shifting the load from the second named prime mover driven generator set to the motor generator set and vice versa.

6. A power plant having a main prime mover driven generator set, motor driven auxiliaries, a prime mover driven set and a motor generator set connected in parallel for supplying power to the motors of the auxiliaries, the motor generator set being connected to the first named generator, and

condensate from the condenser for the main prime mover being utilized as cooling liquid for the condenser of the second prime mover, characterized by the fact that means are provided for automatically holding substantially constant exhaust pressure on the second prime mover by varying the load thereon, the excess load being carried by the motor generator set.

7. In a power plant, a main prime mover, a generator driven thereby, auxiliaries, niotors for driving them, a second prime mover, a generator driven thereby, a motor generator set having its motor connected to the first named generator, means connecting the generator of the motor generator set and the second named generator in parallel to the motors which drive the auxiliaries, a condenser for the main prime mover, a condenser for the second prime mover which utilizes condensate from the first named condenser as cooling liquid, and a movable abutment responsive to the pressure of the second named condenser for automatically regulating the load on the second named prime mover so as to maintain substantially constant vacuum in the second named condenser.

8. In a power plant, a main prime mover, a generator driven thereby, auxiliaries, motors for driving them, a second prime mover, a generator driven thereby, a 'motorgenerator set having its motor connected to the first named generator, means connecting the generator of the motor generator set and the second named generator in parallel to the motors which drive the auxiliaries, acondenser for the main prime mover, a hot well, a jet condenser for the second named prime mover having its discharge tube discharging into the hot well, means for taking condensate from the first named condenser and supplying it to said jet condenser where it is used as cooling water, and automatic means for maintaining such a load on the second named prime mover as to hold substantially constant vacuum in the jet condenser.

9. In a power plant, a main prime mover, a generator driven thereby, auxiliaries, motors for driving them, a second prime mover and a motor which is connected to said generator for supplying power to the motors of the auxiliaries, a condenser for the main prime mover, a condenser for the second prime mover which utilizes condensate from the first named prime mover as cooling liquid, and means for automatically dividing the load between the motor and second named turbine so as to maintain substantially constant vacuum in the second named condenser. I

In witness whereof I have hereunto set my hand this 13th day of December, 1920.

ARTHUR B. SMITH. 

